3.5 P20 hangs - no response

2025-08-10T19:22:47.799000Z

Subject: Solution: CODESYS Freezes Linked to Large Symbol Configuration (OPC UA)

Hello everyone,

I was experiencing the same problem as many here: CODESYS (v3.5 SP20+) freezing during compilation and download, especially on projects that use OPC UA for SCADA. The only workaround was to run Build > Clean
all before every download.

I believe I have found the root cause and a permanent solution.

The Problem:
The issue is directly related to a large Symbol Configuration. In my project, I only need about 700 tags for OPC UA, but the Symbol Configuration list was showing over 250,000 tags. This is because it
automatically includes all variables from Global Variable Lists (GVLs) and other memory areas.

When any static variable is changed, the IDE tries to rebuild this enormous list, causing it to freeze for several minutes.

The Solution:
Instead of letting CODESYS export every variable by default, you can use a pragma to tell it which variables or GVLs to exclude from the symbol export process.

Place the following pragma at the top of any GVL or data structure that you do not want to be part of the symbol configuration:

1 {attribute 'symbol' := 'none'}
2 VAR_GLOBAL
3 // All variables in this GVL will now be excluded from the
4 // Symbol Configuration by default.
5 InternalVariable1 : INT;
6 InternalVariable2 : BOOL;
7 END_VAR

After adding this pragma to all the GVLs that were not needed for OPC UA, the number of tags in my Symbol Configuration dropped to the correct amount. The compilation and download process is now fast again,
with no freezing.

This method is much more efficient than manually managing the symbol list in the editor.

I hope this helps others who are facing this frustrating issue.

Best regards.

3.5 P20 hangs - no response

2025-06-25T13:57:36.009000Z

hi imdatatas,

thanks for you suggestion. I added the process execution for sure.
In the mean time I reïnstall Windows but it dind't help directly.
Finally I deleted CodeMeter Runtime Server after Codesys installation. Because this Service was not ablt to start. And it works (for now) :)!

3.5 P20 hangs - no response

2025-06-25T10:46:41.442000Z

Hi, You can give a try it by adding "Codesys.exe" in the "Exclusions > Process" section of the Windows Security Center or your antivirus program.
I hope it works for your situation.

Antivirus programs check many things during both the installation or startup of an application, and may be slow down or block some functions.

Regards
Imdat

3.5 P20 hangs - no response

2025-06-23T14:16:04.438000Z

Hi, Is there a solution found for the problem described in first post?

Any version above Codesys 3.5 P19 hangs during start up.
It makes no difference whether I simply start Codesys or open a project directly.
I'm using Windows 10 Home edition.

Thanks!

3.5 P20 hangs - no response

2024-06-27T12:36:40.019000Z

Is there anybody can help me with the same problem?
I have to migrate created project in ver.3.5.17.0 32BIT with runtime 4.7.0 to ver.3.5.20.0 64BIT with runtime 4.7.11.0 due to the new license.
All the libraries and dependencies are updaded and there are no any errors. The first compilation and loading to the controller is being compleated well. After this being done and if I am forced to change any values or change any code in the current project, another compilation will be freezed.
This problem can be solved if pressed Build/cleen or cleen all.
There is another method to solve this; if project is loaded with excluded object (Alarm Configuration), repeated compilations will be done well.

3.5 P20 hangs - no response

2024-06-27T10:38:08.983000Z

Colleagues, i have the same problems.

At the current time, I have to use the new version of the Codesys (3.5.20.10) + Control for Linux SL 4.11.0.0, but it works unstable : theree are a lot of freezes and not-respondings.

I tested this on different projects: those that were created in the current version of the project, and those that were migrated from other versions of the development environment.

Compiling a project without connecting to a controller is fast enough. The first downloading of the code into the controller, too. But as soon as you need to make edits and download a new code problems begin. Codesys "freezes" at the "Generation code" stage for 15-20 minutes. And only after that time loads the code into the controller. Previously, we used version 3.5.17.60 + Control for Linux SL 4.7.0.0. The process took 1-2 minutes.

Do you have any ideas how can i fix it? I will be grateful for your answers.

3.5 P20 hangs - no response

2024-06-27T10:38:05.464000Z

Colleagues, i have the same problems.

At the current time, I have to use the new version of the Codesys (3.5.20.10) + Control for Linux SL 4.11.0.0, but it works unstable : theree are a lot of freezes and not-respondings.

I tested this on different projects: those that were created in the current version of the project, and those that were migrated from other versions of the development environment.

Do you have any ideas how can i fix it? I will be grateful for your answers.

3.5 P20 hangs - no response

2024-06-27T10:38:02.110000Z

Colleagues, i have the same problems.

At the current time, I have to use the new version of the Codesys (3.5.20.10) + Control for Linux SL 4.11.0.0, but it works unstable : theree are a lot of freezes and not-respondings.

I tested this on different projects: those that were created in the current version of the project, and those that were migrated from other versions of the development environment.

Do you have any ideas how can i fix it? I will be grateful for your answers.

3.5 P20 hangs - no response

2024-06-24T17:48:38.071000Z

I'm facing the same problem with SP 20 (win 11). is there any solution ?

3.5 P20 hangs - no response

2024-06-24T17:48:34.596000Z

I'm facing the same problem with SP 20 (win 11). is there any solution ?

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